rf107_plotstyles.py

## \ingroup tutorial_roofit_main

## \notebook

## Basic functionality: demonstration of various plotting styles of data, functions in a RooPlot

##

## \macro_image

## \macro_code

## \macro_output

##

## \date February 2018

## \authors Clemens Lange, Wouter Verkerke (C++ version)

import ROOT

# Set up model

# ---------------------

# Create observables

x = ROOT.RooRealVar("x", "x", -10, 10)

# Create Gaussian

sigma = ROOT.RooRealVar("sigma", "sigma", 3, 0.1, 10)

mean = ROOT.RooRealVar("mean", "mean", -3, -10, 10)

gauss = ROOT.RooGaussian("gauss", "gauss", x, mean, sigma)

# Generate a sample of 100 events with sigma=3

data = gauss.generate({x}, 100)

# Fit pdf to data

gauss.fitTo(data, PrintLevel=-1)

# Make plot frames

# -------------------------------

# Make four plot frames to demonstrate various plotting features

frame1 = x.frame(Name="xframe", Title="Red Curve / SumW2 Histo errors", Bins=20)

frame2 = x.frame(Name="xframe", Title="Dashed Curve / No XError bars", Bins=20)

frame3 = x.frame(Name="xframe", Title="Filled Curve / Blue Histo", Bins=20)

frame4 = x.frame(Name="xframe", Title="Partial Range / Filled Bar chart", Bins=20)

# Data plotting styles

# ---------------------------------------

# Use sqrt(sum(weights^2)) error instead of Poisson errors

data.plotOn(frame1, DataError="SumW2")

# Remove horizontal error bars

data.plotOn(frame2, XErrorSize=0)

# Blue markers and error bors

data.plotOn(frame3, MarkerColor="b", LineColor="b")

# Filled bar chart

data.plotOn(frame4, DrawOption="B", DataError=None, XErrorSize=0, FillColor="kGray")

# Function plotting styles

# -----------------------------------------------

# Change line color to red

gauss.plotOn(frame1, LineColor="r")

# Change line style to dashed

gauss.plotOn(frame2, LineStyle="--")

# Filled shapes in green color

gauss.plotOn(frame3, MoveToBack=True, DrawOption="F", FillColor="kOrange")

#

gauss.plotOn(frame4, Range=(-8, 3), LineColor="m")

c = ROOT.TCanvas("rf107_plotstyles", "rf107_plotstyles", 800, 800)

c.Divide(2, 2)

c.cd(1)

ROOT.gPad.SetLeftMargin(0.15)

frame1.GetYaxis().SetTitleOffset(1.6)

frame1.Draw()

c.cd(2)

ROOT.gPad.SetLeftMargin(0.15)

frame2.GetYaxis().SetTitleOffset(1.6)

frame2.Draw()

c.cd(3)

ROOT.gPad.SetLeftMargin(0.15)

frame3.GetYaxis().SetTitleOffset(1.6)

frame3.Draw()

c.cd(4)

ROOT.gPad.SetLeftMargin(0.15)

frame4.GetYaxis().SetTitleOffset(1.6)

frame4.Draw()

c.SaveAs("rf107_plotstyles.png")